Wax coatings are widely used as water-resistant barriers in paper and paperboard products. Boxes made from wax coated board are used for example for carrying food products, such as fruits and vegetables, which are transported in refrigerated spaces where moisture is present. These types of boxes are often coated both internally and externally to provide a good barrier.
However, the high coat weight of wax makes these boxes expensive. Moreover, wax coated products usually made from hot melt coatings are not recyclable or repulpable which makes them less environmental friendly.
Recyclable coatings as an alternative to wax coatings exist. However, they show some drawbacks such as for example difficulties to flute a medium which tends to delaminate during corrugation, difficulties to glue or edge wicking. In some cases, even though the inside and the outside liners of a box are treated, the vent-holes permit the water to go through the flutes thus weakling the structure of the box.
In light of the aforementioned, there is thus a need for new water-resistant coatings as an alternative to known wax coatings which are mostly repulpable and environmental friendly.
There is a need for water-resistant coatings limiting and/or avoiding edge-wicking and showing good runnability on corrugator, on fluting and also gluing.